Strain sensing element, pressure sensor, microphone, blood pressure sensor, and touch panel

Patent metadata

Field	Value
Publication number	US-9654883-B2
Application number	US-201414476200-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 20, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

According to one embodiment, a strain sensing element provided on a deformable substrate includes: a first magnetic layer; a second magnetic layer; a spacer layer; and a bias layer. Magnetization of the second magnetic layer changes according to deformation of the substrate. The spacer layer is provided between the first magnetic layer and the second magnetic layer. The second magnetic layer is provided between the spacer layer and the bias layer. The bias layer is configured to apply a bias to the second magnetic layer.

First claim

What is claimed is:

1. A strain sensing element provided on a deformable substrate, comprising:
a first layer having a first magnetization;
a second layer having a second magnetization to change according to a deformation of the substrate;
an intermediate layer provided between the first layer and the second layer; and
a third layer,
the second layer being provided between the intermediate layer and the third layer,
the third layer including at least one of a first material or a second material,
the first material including at least one selected from the group consisting of Ir—Mn, Pt—Mn, Pd—Pt—Mn, and Ru—Rh—Mn, and
the second material including at least one selected from the group consisting of CoPt (a ratio of Co being not less than 50 at. % and not more than 85 at. %), (Co x Pt 100-x ) 100-y Cr y (x being not less than 50 at. % and not more than 85 at. %, and y being not less than 0 at. % and not more than 40 at. %), and FePt (a ratio of Pt being not less than 40 at. % and not more than 60 at. %).

2. The element according to claim 1 , wherein the first magnetization is pinned.

3. The element according to claim 1 , further comprising:
a fourth layer provided between the third layer and the second layer, the fourth layer being magnetic; and
a fifth layer provided between the fourth layer and the second layer, the fifth layer being non-magnetic.

4. The element according to claim 3 , wherein
the fourth layer includes at least one selected from the group consisting of Co, Fe, and Ni, and
the fifth layer includes at least one selected from the group consisting of Cu, Ru, Rh, Ir, V, Cr, Nb, Mo, Ta, W, Rr, Au, Ag, Pt, Pd, Ti, Zr, and Hf.

5. The element according to claim 3 , further comprising:
a sixth layer provided between the third layer and the fourth layer;
a seventh layer provided between the sixth layer and the fourth layer; and
a relative angle between a magnetization of the fourth layer and a magnetization of the sixth layer is 180°.

6. The element according to claim 3 , wherein the fifth layer includes at least one selected from the group consisting of copper (Cu), gold (Au), silver (Ag), chrome (Cr), ruthenium (Ru), and iridium (Ir).

7. The element according to claim 1 , wherein the third layer applies a magnetic bias to the second layer, and a relative angle between a direction of the magnetic bias in the second layer and the first magnetization is 180°.

8. The element according to claim 1 , wherein the third layer applies a magnetic bias to the second layer, and a relative angle between a direction of the magnetic bias in the second layer and the first magnetization is not less than 90° and not more than 270°.

9. The element according to claim 1 , wherein a coercivity of the second magnetic layer is not more than 10 Oe.

10. The element according to claim 1 , wherein at least one of at least a part of the first layer or at least a part of the second layer is amorphous.

11. The element according to claim 1 , wherein at least one of the first layer or the second layer includes boron.

12. The element according to claim 1 , further comprising:
an eighth layer,
the first layer being provided between the eighth layer and the intermediate layer,
the first magnetization being configured to change according to a deformation,
the eight layer including at least one of a third material or a fourth material,
the third material including at least one selected from the group consisting of Ir—Mn, Pt—Mn, Pd—Pt—Mn, and Ru—Rh—Mn, and
the fourth material including at least one selected from the group consisting CoPt (a ratio of Co being not less than 50 at. % and not more than 85 at. %), (Co x Pt 100-x ) 100-y Cr y (x being not less than 50 at. % and not more than 85 at. %, and y being not less than 0 at. % and not more than 40 at. %), and FePt (a ratio of Pt being not less than 40 at. % and not more than 60 at. %).

13. The element according to claim 12 , further comprising:
a ninth layer provided between the eighth layer and the first layer, the ninth layer being magnetic; and
a tenth layer provided between the ninth layer and the first layer, the tenth layer being non-magnetic.

14. The element according to claim 13 , wherein
the ninth layer includes at least one selected from the group consisting of Co, Fe, and Ni, and
the tenth layer includes at least one selected from the group consisting of Cu, Ru, Rh, Ir, V, Cr, Nb, Mo, Ta, W, Rr, Au, Ag, Pt, Pd, Ti, Zr, and Hf.

15. The element according to claim 13 , further comprising:
an eleventh layer provided between the eighth layer and the ninth layer;
a twelfth layer provided between the eleventh layer and the eighth layer; and
a relative angle between a magnetization of the ninth layer and a magnetization of the eleventh layer is 180°.

16. The element according to claim 15 , further comprising:
a lower first magnetic coupling layer provided between the lower first bias magnetic layer and the lower second bias magnetic layer and configured to cause anti-ferromagnetic coupling to occur between the lower first bias magnetic layer and the lower second bias magnetic layer,
wherein the third layer applies a first magnetic bias to the second layer,
the eighth layer applies a second magnetic bias to the first layer, and
a relative angle between a direction of the first magnetic bias in the second layer and a direction of the second magnetic bias in the first layer is 180°.

17. The element according to claim 13 , wherein
the tenth layer includes at least one selected from the group consisting of copper (Cu), gold (Au), silver (Ag), chrome (Cr), ruthenium (Ru), and iridium (Ir).

18. The element according to claim 12 , wherein
the third layer applies a first magnetic bias to the second layer,
the eight layer applies a second magnetic bias to the first layer, and
a relative angle between a direction of the first magnetic bias in the second layer and a direction of the second magnetic bias in the first layer is 180°.

19. The element according to claim 12 , wherein
a coercivity of the first layer is not more than 10 Oe, and
a coercivity of the second layer is not more than 10 Oe.

20. The element according to claim 12 , wherein
at least one of at least a part of the first layer or at least a part of the second layer is amorphous.

21. The element according to claim 12 , wherein
at least one of the first layer or the second layer includes boron.

22. A pressure sensor comprising:
a support unit;
a substrate supported by the support unit, the substrate being deformable; and
a strain sensing element provided on the substrate, the strain sensing element including
a first layer having a first magnetization,
a second layer having a second magnetization to change according to a deformation of the substrate,
an intermediate layer provided between the first layer and the second layer, and
a third layer,
the second layer being provided between the intermediate layer and the third layer,
the third layer including at least one of a first material or a second material,
the first material including at least one selected from the group consisting of Ir—Mn, Pt—Mn, Pd—Pt—Mn, and Ru—Rh—Mn, and
the second material including at least one selected from the group consisting CoPt (a ratio of Co being not less than 50 at. % and not more than 85 at. %), (Co x Pt 100-x ) 100-x Cr y (x being not less than 50 at. % and not more than 85 at. %, and y being not less than 0 at. % and not more than 40

Assignees

• Toshiba Kk

Inventors

• Fuji Yoshihiko
• Fukuzawa Hideaki
• Kaji Shiori

Classifications

• H04R2201/003

  Mems transducers or their use · CPC title

• G01L1/125

  by using magnetostrictive means (magnetostrictive sensors H10N35/101) · CPC title

• H04R23/00 Primary

  Transducers other than those covered by groups H04R9/00 - H04R21/00 {(diaphragms for transducers of the distributed-mode type H04R7/045)} · CPC title

• H04R2410/03

  Reduction of intrinsic noise in microphones · CPC title

• G01L9/0041

  Transmitting or indicating the displacement of flexible diaphragms · CPC title